JPH06477B2 - Control circuit of constant-speed traveling device for vehicle - Google Patents

Description

TECHNICAL FIELD The present invention relates to a control circuit for a vehicle constant speed traveling device.

<Prior Art> Generally, various constant speed traveling devices for maintaining a vehicle speed at a predetermined set speed have been known. According to such a constant speed traveling device, by operating the accelerator pedal to operate the set switch when a desired vehicle speed is reached,
An actuator that operates in the same manner as the accelerator pedal operates, and even if the foot is subsequently released from the accelerator pedal, the vehicle speed can be maintained at the set speed.

As an actuator of such a constant speed traveling device, there is an actuator using a motor type actuator which has a relatively compact structure and can be controlled with high accuracy. A control circuit for accelerating and decelerating by this motor type actuator is provided, for example, in Japanese Utility Model Publication No.
The actuator drive circuit having the acceleration and deceleration drive circuits may be configured by using the transistor bridge circuit disclosed in the '98 specification.

The control circuit of such a constant speed traveling device has a so-called fail-safe function, and even if any one of the switches that interlock with the brake pedal, the clutch pedal, or the shift position during constant speed traveling is used. When operated, a deceleration signal is generated from the CPU as the control means, and the actuator is driven to the deceleration side via the drive circuit. Then, since the automatic constant-speed traveling state is released to enter the normal traveling state, it is possible to decelerate and stop the vehicle, for example, at the driver's will.

By the way, in such a transistor bridge circuit, when the power transistor of the acceleration drive circuit is short-circuited, the acceleration drive circuit continues to operate regardless of the control signal, and the actuator is driven to the acceleration side. Becomes Therefore, because the vehicle speed increases, if you try to stop the vehicle by operating the brake pedal, the fail-safe function works and the deceleration side drive circuit also operates, but the acceleration side current also flows. As a result, the actuator is unlikely to move toward the deceleration side, and the engine brake may not work properly. In this case, the main switch of the constant speed traveling device may be turned off, but there is a problem that the stop operation is troublesome.

Further, in the actuator drive circuit using the transistor bridge circuit described above, the present inventor has noticed that the power supply for the acceleration and deceleration drive circuits is branched from one common line.

<Problems to be Solved by the Invention> In view of the problems of the prior art and the knowledge of the present inventor, the main object of the present invention is to step the brake even if the acceleration drive circuit of the actuator is short-circuited. An object of the present invention is to provide a control circuit for a vehicle constant speed traveling device that can shut off the power supply of the acceleration drive circuit to prevent the actuator from operating on the acceleration side.

<Means for Solving the Problems> According to the present invention, the object is to control the vehicle speed based on the control signal and control means for performing arithmetic control to maintain the vehicle speed at the set vehicle speed. Control of a vehicle constant-speed traveling device having an acceleration and deceleration drive circuit including a transistor circuit for driving an actuator that operates, and a magnet clutch drive circuit provided in a drive force transmission path of the actuator In the circuit, the main power switch of the control circuit, a contact that opens when the vehicle brakes are depressed, the drive circuit of the magnet clutch, and the acceleration drive circuit are connected in series,
The present invention is achieved by providing a control circuit for a vehicle constant speed traveling device, characterized in that the power source of the deceleration drive circuit is branched immediately after the main power switch.

<Operation> In this way, the power supply to the drive circuit of the magnet clutch and the drive circuit for acceleration is reliably cut off by pressing the brake, and even if the brake is pressed when the vehicle is not in the constant speed traveling control state. Unnecessary current does not flow in the circuit. Further, since the power source of the drive circuit for deceleration is branched from before the brake switch, the deceleration control of the actuator is surely performed even if the magnetic clutch of Yoshiba is mechanically locked.

<Embodiment> Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a circuit diagram showing a schematic configuration of a vehicle constant speed traveling device according to the present invention. The control of the constant speed traveling device is connected to the power supply circuit 2, the input control circuit 3, the input / output control circuit 4, the actuator drive circuit 5, the motor current detection circuit 6, and these circuits provided in the control unit 1. It is performed by a control circuit having a CPU 7 that performs arithmetic processing according to the above.

The control unit 1 is supplied with a voltage supplied from a battery 11 as a power source via an ignition switch 8, a fuse 9 and a main switch 10 via a terminal T1. The power supply circuit 2 is connected to the terminal T1, and the voltage stabilized in the power supply circuit 2 is supplied to the CPU 7. A power supply terminal Vb is provided between the terminal T1 and the power supply circuit 2 and a stabilized power supply terminal Vc is provided in the power supply circuit 2 for power supply of other circuits of the control unit 1. The other end of the main lamp 12 whose one end is grounded is connected between the main switch 10 and the terminal T1. The signal from the vehicle speed sensor 13 is input to the input control circuit 3 via the terminal T2, and the signals from the set switch 15 and the resume switch 16 connected to the battery 11 via the common fuse 14 are respectively input to the terminal. Input is made so that the operation of the CPU 7 can be instructed via T3 and T4.

Signals from the contacts S1 and S2 of a brake switch 21 attached to a brake pedal (not shown) are supplied to the control unit 1 as its control input from terminals T5 and T6.
Be entered via. The contact point S1 is a normally open contact point, is connected between a fuse 17 and a terminal T5 that are provided so as to branch from between the battery 11 and the ignition switch 8, and the contact point S2 is a normally closed contact point, and is a main switch. It is connected between 10 and the terminal T1 and between the terminal T6. As a control input, a signal from a clutch switch 22 attached to a clutch pedal (not shown) is input via a terminal T7.

The terminals T8 to T10 of the control unit are connected to the motor-type actuator 23, the terminal T8 is connected to the coil 24a of the magnet clutch 24 built in the actuator 23, and the terminals T9 and T10 are connected to the motor 2.
5 are connected respectively. This actuator 23
Drives the accelerator pedal (not shown) via a linkage (not shown) that is integrally operated via the magnet clutch 24 by rotating the motor 25 in the forward and reverse directions. The terminal T10 is an output terminal for accelerating the vehicle, and a limit switch 26 for preventing overrun of the motor 25 is connected between the terminal T10 and the motor 25. Further, the terminal T9 is an output terminal on the side for decelerating the vehicle.

One end of a cruise lamp 27 for indicating that the constant speed traveling device is operating is connected to the control unit 1 via a terminal T11, and the other end is grounded via a known dimming circuit 28. Has been done. The control unit 1 is grounded via the terminal T12.

In the control unit 1, terminals T5, T
7, T11 are connected to the CPU 7 via the input / output control circuit 4. The emitter of the power transistor Q1 is connected to the terminal T6, and the collector of the power transistor Q1 is connected to the terminal T8. In addition, a varistor Z is provided between the emitter and collector of the power transistor Q1.
N is connected, and the diode D1 directs the cathode to the emitter and the anode to the collector, and the varistor Z.
It is connected in parallel with N. A resistor R1 is connected between the emitter and base of the power transistor Q1 and the base of the power transistor Q1 is connected to the collector of the power transistor Q2 via the resistor R2. The power transistor Q2 is grounded at its emitter, and its base is connected to the terminal C1 of the CPU 7 via the input / output control circuit 4. The output signal from the CPU 7 turns on or off the coil 24a of the magnet clutch 24. Become. The anode of the diode D2 is connected to the collector of the power transistor Q1,
The cathode of the diode D2 is connected to the terminal C2 of the CPU 7 via the input / output control circuit 4.

The actuator drive circuit 5 is composed of a well-known transistor bridge circuit in order to rotate the motor 25 forward and backward according to the control output signal of the CPU 7. Then, in the actuator drive circuit 5, the acceleration drive circuit 3 for driving the actuator 23 to the side that accelerates the vehicle.
1 is configured to pass a current from the power transistor Q3 to the power transistor Q4, and the deceleration drive circuit 32 on the side for decelerating the vehicle is configured to pass a current from the power transistor Q5 to the power transistor Q6. That is, as shown in the figure, the collector of the power transistor Q3 is connected to the collector of the power transistor Q4 via the terminal T10, the limit switch 26, the motor 25, and the terminal T9, and the collector of the power transistor Q5 is Power transistor Q via terminal T9, motor 25, limit switch 26, terminal T10
It is connected with 6 collectors. The emitters of the power transistors Q4 and Q6 are grounded via the motor current detection circuit 6. The motor current detection circuit 6 is also connected to the terminal C3 of the CPU 7.

Diodes D3 and D5 are connected to the power transistors Q3 and Q5, respectively, with the cathode facing the emitter and the anode facing the collector. Power transistor Q
Diodes D4 and D6 are connected to 4 and Q6, respectively, with the cathode facing the collector and the anode facing the emitter. Resistors R3 to R6 are connected between the emitters and bases of the power transistors Q3 to Q6, respectively. The bases of the power transistors Q3 to Q6 are connected to the transistors Q7 to Q6 via resistors R7 to R10.
The collectors of Q10 are connected to each other. Further, the bases of the transistors Q7 and Q9 together with the emitters thereof are also grounded via the resistors R11 and R13.
The emitters of the transistors Q8 and Q10 as well as their respective bases are connected to the stabilized power supply Vc via resistors R12 and R14 and power supply lines (not shown). The bases of the transistors Q7 to Q10 are connected to the signal output terminals C4 to C7 of the CPU 7 via the resistors R15 to R18, respectively.

By the way, the emitter of the power transistor Q3 is connected to the cathode of the diode D2 described above, and the voltage from the battery 11 is used as the power supply voltage of the acceleration drive circuit 31 for the ignition switch 8, the fuse 9, the main switch 10, and the brake switch 21. It is supplied via the contact S2 and the clutch drive circuit 29. Then, the voltage from the power supply terminal Vb branched immediately after the power supply input terminal T1 is supplied to the emitter of the power transistor Q5 as the power supply voltage of the deceleration drive circuit 32 so as to be separated from the power supply of the acceleration drive circuit 31. Has been done.

Next, the operation of the constant speed traveling device thus configured will be described.

By closing the main switch 10 with the ignition switch 8 closed, the power supply voltage is supplied to the control unit 1 and the main lamp 12
Lights up. When the set switch 15 is closed and, for example, the condition that the brake switch 21 and the clutch switch 22 are not operated is satisfied, the CPU 7 stores the vehicle speed at that time as a set vehicle speed by a signal from the vehicle speed sensor 13. The cruise lamp 27 lights up.

Next, when the actuator 23 is driven according to the difference between the set vehicle speed and the actual vehicle speed, the CPU 7 outputs a signal for turning on the magnet clutch 24, and the coil 24 is turned on.
When a is energized, the magnet clutch 24 is brought into a connected state. The acceleration or deceleration signal is sent to the terminal C4 of the CPU 7.
Output from C7 to C7 respectively, the acceleration or deceleration drive circuits 31 and 32 are turned on to rotate the motor 25, and control is performed so that the actual vehicle speed and the set vehicle speed substantially match. The resume switch 16 is pressed to release a new set vehicle speed when the desired vehicle speed is raised to C.
It is to be stored in the PU 7.

Further, when the CPU 7 detects that the brake switch 21 or the clutch switch 22 is operated, for example, the constant speed traveling state is released. At this time, in order to drive the actuator 23 in the decelerating direction, the CP
A deceleration signal is output from U7 to the actuator drive circuit 5, the vehicle is decelerated, and the cruise lamp 27 is turned off.

In the constant-speed traveling device thus configured, the power supply voltage of the acceleration drive circuit 31 of the actuator drive circuit 5 is set to a system different from the power supply of the deceleration drive circuit 32 as described above. , And the contact S of the brake switch 21
2 and the power transistor Q1 for driving the clutch, the contact S2 of the brake switch 21 is opened by stepping on the brake, and the power of the power transistor Q1 and the acceleration drive circuit 31 is cut off. Become. Therefore, for example, even when the power transistors Q3 and Q4 of the acceleration drive circuit 31 are short-circuited, the coil 24a of the magnet clutch 24 and the motor 25 of the actuator 23 are energized in a direction to drive the motor 25 toward the acceleration side. There is no.

In this embodiment, the motor type actuator is shown, but any actuator of the constant speed traveling device may be used. For example, in the case of a negative pressure type actuator, the power source voltage of the drive circuit of the solenoid valve for accelerating the vehicle. Should be supplied via the brake switch.

<Effects of the Invention> In this way, by supplying the power supply voltage of the acceleration drive circuit for driving the actuator to the side accelerating the vehicle through the brake switch attached to the brake pedal, the brake pedal can be depressed. Since the power supply of the acceleration drive circuit of the actuator is cut off, the actuator is not driven to the acceleration side. Therefore, even if the transistor of the acceleration drive circuit is short-circuited, by depressing the brake pedal, the side that accelerates the actuator is not energized, and the vehicle can be decelerated appropriately. Moreover, the power supply for the deceleration drive circuit uses a system in which the normally closed contact of the brake switch is separate from the magnet clutch and the acceleration drive circuit, so even if the magnetic clutch cannot be mechanically disengaged, deceleration control will be performed reliably. Be seen.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration of a constant speed traveling device according to the present invention. 1 ... Control unit 2 ... Power supply circuit 3 ... Input control circuit 4 ... Input / output control circuit 5 ... Actuator drive circuit 6 ... Motor current detection circuit 7 ... CPU 8 ... Ignition switch 9 ... Fuse 10 ... Main switch 11 ... Battery 12 ... Main Lamp 13 ... Vehicle speed sensor 14 ... Fuse 15 ... Set switch 16 ... Resume switch 17 ... Fuse 21 ... Brake switch 22 ... Clutch switch 23 ... Actuator 24 ... Magnet clutch 24a ... Coil 25 ... Motor 26 ... Limit switch 27 ... Cruise lamp 28 ... Dimming circuit 31 ... Acceleration drive circuit 32 ... Deceleration drive circuit

Claims (1)

[Claims] 1. An accelerating and decelerating device comprising control means for performing arithmetic control to maintain a vehicle speed at a set vehicle speed and generating a control signal, and a transistor circuit for driving an actuator for performing a vehicle speed control operation based on the control signal. A control circuit for a vehicle constant speed traveling device having a drive circuit for a vehicle and a drive circuit for a magnet clutch provided in a drive force transmission path of the actuator, wherein a main power switch of the control circuit and a brake for the vehicle are provided. The contact that opens when stepping on, the drive circuit of the magnet clutch, and the acceleration drive circuit are connected in series, and the power supply of the deceleration drive circuit is branched immediately after the main power switch. A control circuit for a constant-speed traveling device for a vehicle.